From 1991 he is affiliated with the Systems Research Institute of the
Polish Academy of Sciences, from which he received his scientific
degrees.He is also Professor in Graduate School for Applied Informatics and Management in Warsaw.

The scientific interests of Professor Kaliszewski are in
optimization, multiple criteria decision making, computer-aided decision
making, and also in identification, quantification, and management of risk
in business organizations.

He confronts his scientific interests
and achievements in realm of business.

In 1994 - 1995 he worked as an analyst in Polish Development
Bank.

In years 1995 - 1996 he worked on establishing Warsaw Board of
Trade, and in years 1997 - 2003 in National Depository for
Securities (a depository and a clearing house) on a clearing system for
derivative trading on Warsaw Stock Exchange and Electricity
Exchange.

In 2004 - 2005 he was the advisor to CEO and the leader of a
team implementing New Basel Accord in BISE bank.

In 2007 - 2008 he held position of Scientific Secretary in Instute of Mathematical Machines.

In 2008 - 2009 he was proxy to CEO, and in 2009 - 2010 he acted as director of Scientific Office in Telecommunication Institute (Przemysłowy Instytut Telekomunikacji S.A.)